Electric signal-gong.



No. 7|7,l37. Patented Dec. 30, I902. H. C. THOMPSON.-

ELECTRIG SIGNAL GONG.

(Application filed July 29, 1902.)

- (No Model.)

w A 4 a r 5 I i v w v f/AMW/JV/l/l/AIII [Il /IAIN lll V/AL'ELVA fiv dag milk W UNTTnb' STATES ATENT .FFICE.

HENRY U. THOMSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO ELECTRIC GAS LIGHTING COMPANY, OF BOSTON, MASSACHUSETTS.

ELECTRIC SIGNAL-GONG.

.SJEECIFICATION forming part of Letters Patent no. 717,137, dated December 30, 1

Application filed July 29,1902. Serial No. 117,440. (No model.)

To all whom, it may concern:

Be it known that I, HENRY O. THOMSON, a citizen of the United States, residing at Boston, Massachusetts, have invented a new and 5 usefullmprovementinElectricSignal-Gongs,

of which the following is a specification.

My invention relates to ordinary electrical signal or call bells in which two gongs are struck by one hammer, frequently called vi- IO brators; and myinvention has for its object to obtain the normal and preferable tone which has hitherto been muffled and injured by reason of the necessary contiguity of the two gongs, and also to avoid the objection of the single hammer remaining too long near to the second gong, and also to get over the difficulties of adjustment between two gongs and one hammer, which even when carefully made leave the apparatus objectionable, as

above indicated.

My invention consists in the new parts and their combination,substantiallyas illustrated in the drawings hereto annexed, in which-- Figure 1 is a partly-sectional view of my invention. Fig. 2 is a modification.

The gongs A A are properly supported in the case C by the pillars a ct, and in this case is an electromagnet it supported by base 71 (partially shown by dotted lines,) having the g, which is pivoted upon h, said armature c, as shown, branching into the two forks d d, passing through apertures in the case 0 and one carrying the hammer D and the other the hammer D, said armature e also carrying the small fiat spring f, which normally presses against the adjusting-post j, which is insulated from and secured to extension h of base h. From the binding-post it passes the wire Z to the magnet-helix 2', connected with vibrating armature 6 mon nted u pon the springthe helix 1', from which the circuit continues to the metallic part of the supporting insulated lugj. The binding-post 7c is connected by the wire at to the frame h. The armature 6 may of course be in two parts, if preferred, as shown in Fig. 2.

The operation of my invention will be plain. Upon energizing the magnet from the callingstation by the ordinary push-button the armature e is attracted, causing the hammer D to strike upon the gong A and the hammer D to strike upon the gong A. The vibrational movement breaks the circuit betweenj and f, and the armature e being released and flying back reestablishes the circuit, causing a rope tition of the operation,whicl1 continues as long as the calling push-button is pressed.

Having described my invention, what I claim is- An electric signal-gong composed of an elec- 6o tromagnet properly mounted, a vibrating armature 6 split into two forks d d, a hammer on each fork, an adjustment-postj, a spring fattached to said armature e and bearing against said postj, and two gongs, one in proximity to one hammer and the other in proximity to the other hammer, and circuit connections whereby, upon and during the energizing of said magnet by the usual pushbutton and the attraction of said armature thereby, the circuit may be made and broken as often as vibration of said hammers occurs; substantially as described and shown.

In witness whereof I hereunto set my hand this 28th day of July, 1902.

HENRY O. THOMSON.

In presence of FRED G. CHAMBERLIN, MICHAEL LUoEY. 

